I recently got a Claro Halo XT for HTPC duties (movies mainly). I'm using a Harman Kardon Signature 2.1 power amplifier and Jamo C80 series speakers.

I want to roll some op-amps in it and I have some questions:

1) What's the voltage this card runs it's op-amps at?
2) I see there's an I/V and a buffer position on the HALO card and just three dual opamps on the XT daughter board. What do the op-amps on the daughter board do, I/V or Buffer?
2') If the do I/V, are those outputs buffered with another opamp/buffer? I want to run the same opamps/buffers on all channels if possible.
3) I noticed there are two buffer sockets, is one for the stereo out and one for headphones? If it is, it makes sense to use different buffers there ...

I was thinking about AD797BR on adapters for I/V (seems a safe choice) and for buffers I don't have any idea ... BUF634? Please specify if you actually tested the op-amp in this sound card if you recommend one ...

In the mean time I received some answers from HT Omega (which I might add, seem to threat their customers well and actually respond to questions well and fast). The answers:

- The Zout of the headphone jack is 8ohm.
- The Zout of the rca's is 150ohm. Both acceptable I think, unless you have Grado's and you like super tight bass.
- The card runs it's op-amps at 12V.
- The opamps on the XT are buffers.
- The recommend the LME49790NA and the OPA2132P. They have users reporting success with OPA627 (ha!) and users asking about AD797 but no reports with it.

So, can I use AD797 all around and BUF634 in the buffer position on the main card? What are some safe (tested) opamps for this card?

I am on the cusp of getting this sound card. I do not have onboard S/PDIF on my motherboard, and I'm trying to use this for connecting to my Astro MixAmp with A40's, along with being connected to my speakers via RCA. Also, I may be trying to capture sound via S/PDIF off my PS2 once I get a good video capture card. My questions are, is this going to be good for that sort of set up? Would I get better game sounds if I plug my headphones into the card (I didn't see Dolby Headphone supported)?

I recommend the LT1364 for this card, It really brings the midbass punch and it sounds for the lack of a better word, more analogue. It's miles better than the stock JRC4580D especially on headphones, I really didn't expect that from a simple opamp swap.